Motor vehicle forward vision data generated by a video camera mounted at or near the driver's eye level can be processed to identify various items of interest such as roadway lane markers. The vision system can then determine the location of the vehicle relative to the lane markers, for displaying video information to the driver or for detecting lane changing and/or driving patterns indicative of a drowsy driver. Most of these applications require lane marker detection in a region of about 5–30 meters forward of the vehicle, where the lane markers can be reliably approximated as straight lines. However, dashed or periodic lane markers can have relatively large gaps, and frequently only a fraction of a lane marker is visible to the camera in any given video frame, particularly in mechanizations where a portion of the roadway within the video frame is obscured by the hood or fenders of the vehicle. Since this can degrade the ability of the lane tracking system to perform the intended functions, it would be beneficial if the information obtained from successively generated video images could be consolidated to provide more complete lane marker data, either for display or lane detection purposes.